Apparatus for automatically supplying oil to a hot strip mill

ABSTRACT

Apparatus for automatically supplying oil to a four-high hot strip mill includes oil sprays for the back-up rolls and a continuously operating pump for supplying oil through a three-way valve either to the sprays or to a recirculating system. A strip detector on the exit side of the mill positions the three-way valve to supply oil to the sprays when it first detects the leading end of the strip and a strip detector on the entry side of the mill positions the three-way valve to recirculate the oil shortly before the trailing end of the strip reaches the mill. The control system may be used with other types of mills and workpieces.

United States Patent Long, Jr, et al.

[ Mar. 14, 1972 [54] APPARATUS FOR AUTOMATICALLY SUPPLYING OIL TO A HOT STRIP MILL Inventors: Alvah C. Long, Jr., Peters Township, Al-

legheny County; Edward J. Stolic, Bethel Park Borough, both of Pa.

United States Steel Corporation Feb. 18, 1970 Assignee:

Filed:

Appl. No.:

References Cited UNITED STATES PATENTS 11/1934 Clark ..72/201 Primary Examiner-Charles E. Lanham Assistant Examiner-E. M. Combs Att0rneyMartin J. Carroll [5 7] ABSTRACT Apparatus for automatically supplying oil to a four-high hot strip mill includes oil sprays for the back-up rolls and a continuously operating pump for supplying oil through a threeway valve either to the sprays or to a recirculating system. A strip detector on the exit side of the mill] positions the threeway valve to supply oil to the sprays when it first detects the leading end of the strip and a strip detector on the entry side of the mill positions the three-way valve to recirculate the oil shortly before the trailing end of the strip reaches the mill, The control system may be used with other types of mills and workpieces.

10 Claims, 1 Drawing Figure APPARATUS FOR AUTOMATICALLY SUPPLYllNG OIL TO A HOT STRIP MILL This invention relates to apparatus for automatically supplying oil to a hot mill and more particularly to supplying oil to the work rolls of the finishing and roughing stands of a fourhigh mill while a hot steel strip is being reduced. With previous systems it was difficult to control the oil film thickness. When a heavy oil film is present on the work rolls before the strip enters the rolls, the strip may cobble which results in lost production. Also, since some of the oil burns when it contacts the red hot strip, an unpredictable oil film is a potential fire hazard.

It is therefore an object of our invention to provide apparatus which completely or partially eliminates the disadvantages set forth above.

Another object is to provide such apparatus which feeds oil to the backup rolls only after the leading end of the strip has passed through the work rolls and stops feed of oil to the backup rolls before the trailing end of the strip reaches the work rolls.

These and other objects will be more apparent after referring to the following specification and attached drawing, in which:

The single FIGURE is a schematic view of our invention as applied to a four-high strip mill.

Referring more particularly to the drawing, reference numeral 2 indicates a four-high hot rolling mill stand having work rolls 4 and backup rolls 6. A spray 8 extends across the width of top backup roll 6 and a spray 10 extends across the width of bottom backup roll 6. A combination wiper and deflector plate 12 protects the spray it) from water. Oil is supplied to the sprays 8 and 10 from a reservoir 14 through a first conduit 16 having a pump 18 therein, a three-way solenoid valve 20 at the end of conduit 16, and a second conduit 22. A third conduit 24 leads from the valve 20 to the reservoir 14. A first strip detector 26 is positioned adjacent the path of travel of strip S a short distance beyond the exit end of the mill stand 2 and a second strip detector 28 is positioned adjacent the path of travel of strip S a short distance from the entry side of the mill stand 2. The detectors 26 and 28 are conventional and generate electric signals which control relay coils 30 and 32, respectively, in a conventional way. Coils 30 and 32 have normally open contacts 30C and 32C which are connected to power source L1, L2 in series with solenoid 208 of valve 20.

In operation, the pump 18 is operated all the time that the mill is running. This gives maximum speed of response. When there is no strip in the mill the valve 20 will be in the position which connects conduits l6 and 24 so that the oil merely circulates. When the leading end of a strip S is detected by detector 28, contact 32C closes, but contact 30C remains open until the leading end of the strip is detected by detector 26. When this occurs solenoid 205 is energized, which moves valve 20 to connect conduits l6 and 22, thus supplying oil to sprays 8 and 10 which spray oil on the back-up rolls 6 which in turn transfers the oil to work rolls 4. This continues until the trailing end of the strip S passes detector 28 which then causes contact 32C to open to deenergize solenoid 20S and move valve 20 to connect conduits l6 and 24. When the trailing end of the strip passes detector 26, contact 30C opens so that the system is reset to original condition.

While one embodiment of our invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

We claim:

1. Apparatus for automatically supplying oil to the rolls of a hot rolling mill stand through which a workpiece passes which comprises oil spray means for said mill stand, means for supplying oil to said spray means, means for initiating operation of said oil supply means shortly after the leading end of said workpiece passes through said mill stand, and means for stopping operation of said oil supply means shortly before the trailing end of said workpiece reaches said mill stand.

2. Apparatus according to claim 1 in which said means for initiating operation of said oil su ply means includes a first workpiece detector on the exit 81 e of said rolling mill stand,

and said means for stopping operation of said oil supply means includes a second workpiece detector on the entry side of said rolling mill stand.

3. Apparatus according to claim 1 in which said means for supplying oil to said spray means includes a reservoir for said oil, a conduit connected to said reservoir, and a pump in said conduit.

4. Apparatus according to claim 3 in which said means for initiating operation of said oil supply means includes a first workpiece detector on the exit side of said rolling mill stand, and said means for stopping operation of said oil supply means includes a second workpiece detector on the entry side of said rolling mill stand.

5. Apparatus according to claim l in which said means for supplying oil to said spray means includes a reservoir for said oil, a three-way valve, 'a first conduit leading from said reservoir to said valve, a pump in said first. conduit, a second conduit leading from said valve to said spray means, a third conduit leading from said valve to said reservoir, a solenoid for operating said valve, said valve being positioned to connect said first and third conduits when said solenoid is not energized, and a circuit including two contacts and said solenoid connected in series; said means for initiating operation of said oil supply means includes a first workpiece detector on the exit side of said rolling mill stand operable to close one of said contacts when a workpiece is present and to open it when a workpiece is absent; and said means for stopping operation of said oil supply means includes a second workpiece detector on the entry side of said rolling mill stand operable to close the other of said contacts when a workpiece is present and to open it when a workpiece is absent.

6. Apparatus according to claim 1 in which said workpiece is a strip, said rolling mill stand includes a pair of work rolls and a back-up roll for each work roll, and said oil spray means includes an oil spray positioned to direct oil on each backup roll.

7. Apparatus according to claim 6 in which said means for initiating operation of said oil supply means includes a first strip detector on the exit side of said rolling mill stand, and said means for stopping operation of said oil supply means includes a second strip detector on the entry side of said rolling mill stand.

8. Apparatus according to claim 6 in which said means for supplying oil to said spray means includes a reservoir for said oil, a conduit connected to said reservoir, and a pump in said conduit.

9. Apparatus according to claim 6 in which said means for supplying oil to said spray means includes a reservoir for said oil, a three-way valve, a first conduit leading from said reservoir to said valve, a pump in said first conduit, a second conduit leading from said valve to said spray means, and a third conduit leading from said valve to said reservoir.

10. Apparatus according to claim 9 in which said means for initiating operation of said oil supply means includes a first strip detector on the exit side of said rolling mill stand, means operable by said first strip detector when a strip is detected for positioning said valve to connect said first and second conduits; and said means for stopping operation of said oil supply means including a second strip detector on the entry side of said rolling mill, and means operable by said second strip detector when the trailing end of a strip is detected for positioning said valve to connect said first and third conduits. 

1. Apparatus for automatically supplying oil to the rolls of a hot rolling mill stand through which a workpiece passes which comprises oil spray means for said mill stand, means for supplying oil to said spray means, means for initiating operation of said oil supply means shortly after the leading end of said workpiece passes through said mill stand, and means for stopping operation of said oil supply means shortly before the trailing end of said workpiece reaches said mill stand.
 2. Apparatus according to claim 1 in which said means for initiating operation of said oil supply means includes a first workpiece detector on the exit side of said rolling mill stand, and said means for stopping operation of said oil supply means includes a second workpiece detector on the entry side of said rolling mill stand.
 3. Apparatus according to claim 1 in which said means for supplying oil to said spray means includes a reservoir for said oil, a conduit connected to said reservoir, and a pump in said conduit.
 4. Apparatus according to claim 3 in which said means for initiating operation of said oil supply means includes a first workpiece detector on the exit side of said rolling mill stand, and said means for stopping operation of said oil supply means includes a second workpiece detector on the entry side of said rolling mill stand.
 5. Apparatus according to claim 1 in which said means for supplying oil to said spray means includes a reservoir for said oil, a three-way valve, a first conduit leading from said reservoir to said valve, a pump in said first conduit, a second conduit leading from said valve to said spray means, a third conduit leading from said valve to said reservoir, a solenoid for operating said valve, said valve being positioned to connect said first and third conduits when said solenoid is not energized, and a circuit including two contacts and said solenoid connected in series; said means for initiating operation of said oil supply means includes a first workpiece detector on the exit side of said rolling mill stand operable to close one of said contacts when a workpiece is present and to open it when a workpiece is absent; and said means for stopping operation of said oil supply means includes a second workpiece detector on the entry side of said rolling mill stand operable to close the other of said contacts when a workpiece is present and to open it when a workpiece is absent.
 6. Apparatus according to claim 1 in which said workpiece is a strip, said rolling mill stand includes a pair of work rolls and a back-up roll for each work roll, and said oil spray means includes an oil spray positioned to direct oil on each back-up roll.
 7. Apparatus according to claim 6 in which said means for initiating operation of said oil supply means includes a first strip detector on the exit side of said rolling mill stand, and said means for stopping operation of said oil supply means includes a second strip detector on the entry side of said rolling mill stand.
 8. Apparatus according to claim 6 in which said means for supplying oil to said spray meAns includes a reservoir for said oil, a conduit connected to said reservoir, and a pump in said conduit.
 9. Apparatus according to claim 6 in which said means for supplying oil to said spray means includes a reservoir for said oil, a three-way valve, a first conduit leading from said reservoir to said valve, a pump in said first conduit, a second conduit leading from said valve to said spray means, and a third conduit leading from said valve to said reservoir.
 10. Apparatus according to claim 9 in which said means for initiating operation of said oil supply means includes a first strip detector on the exit side of said rolling mill stand, means operable by said first strip detector when a strip is detected for positioning said valve to connect said first and second conduits; and said means for stopping operation of said oil supply means includes a second strip detector on the entry side of said rolling mill, and means operable by said second strip detector when the trailing end of a strip is detected for positioning said valve to connect said first and third conduits. 